Air Purging - Carrier 38BC Installation Manual

38BC / 38BH
Refrigerant connections
Three-way valve (gas)
Needle valve
Valve cap
Valve needle
Allen (hex. head) wrench
Three-way valve (liquid)
Flare nut
Liquid line (small diameter)
Gas line (large diameter)
Indoor unit
Outdoor unit
Vacuum pump

Air purging

Use only a vacuum pump to purge air from the piping.
NEVER use the system compressor as a vacuum pump.
NEVER use the unit refrigerant gas to purge the connecting
pipes.
No additional refrigerant has been provided in the unit for this
purpose.
Remove the caps from the three-way valves.
Create a vacuum with a vacuum pump connected to the service
connection of the suction shut-off valve (gas), as shown, keeping
the shut-off valves completely shut until a 50 Pa (0.5 mbar)
vacuum has been reached.
Now open the liquid valve for 3 seconds, then quickly shut it to
check for possible leaks.
After the leak check, fully open the three-way valves.
Replace caps and check for leaks.
Once all connections have been completed, check for leaks by
using a leak detector specific for HFC refrigerants.
GB - 8
R-410A
Finally wrap the valves and pipes with anti-condensate insulation
and tighten this with tape, without exerting too much pressure on
the insulation.
Repair and cover any possible cracks in the insulation.
Fix the pipes to the wall with hooks or conduits.
Pipe
Pipe insulation
Fastening tape